Control means for fluid pressure operated devices



Dec. 27, 1949 l D. G. GRISWOLD- 2,492,859

CONTROL MEANS FOR FLUID PRESSURE OPERATED DEVICES originl Filed May 1, 1940 f 405 kif/@J 2.; 0f is;

Patented Dec. 27, 1949 UNITED STATES PATENT OFFICE CONTROL MEANS FOR FLUID PRESSURE OPERATED DEVICES Donald G. Griswold, Alhambra, Calif., assigner to Clayton Manufacturing Company, Alhambra, u

Calif.

6 Claims.

The present invention relates to automatic means for controlling the rate of operation of fluid pressure operated devices.

More particularly, the invention relates to a control unit for rendering a fluid pressure operated valve self-governing, the control unit being designed to control the operation of the valve so that the valve will at all times operate eiiiciently and quietly, and open automatically whenever the Y pressure on one side of the valve is greater than that on the other side of the valve and to close automatically when the pressure conditions are reversed.

The present application is a division of my copending application Serial No. 332,824, filed May 1, 1940, and entitled Pressure responsive valves, and which application has matured into Patent 2,366,144.

The principal object of the invention is to provide automatic control means for pressure fluid operated valves which will control both the opening and closing rates of such valves.

Another object of the invention is to provide automatic control means for fluid pressure operated valves which will control the closingI action of the valve in such manner as to avoid chattering, hammering and line shock.

Another object of the invention is to provide a control unit for a fluid pressure operated valve by means of which both the opening and closing action of the valve may be regulated and controlled so that at least the closing action will be uniformly slow, and the opening action substantially unretarded so that the valve can be reopened to its fullest extent without undue delay.

Another object of the invention is to provide control means for a fluid pressure operated valve whereby the period of closing and opening of the valve may be varied as desired to meet specific conditions; for example, in certain installations employing large diameter pipe lines of great length and valves of large size, a total closing period of one to two minutes or more may be necessary to cut off flow without producing line shock or hammering, whereas it may be desirable to have the valve open substantially immediately to resume flow.

A further object of the invention is to provide a i control device for a check valve which will render the check valve positive in its operation so that it will not waiver or flutter between opened or closed positions, but which in normal operation will maintain the valve either completely closed or fully open; complete closing avoiding Y undesirable leakage through the valve, and full 2 opening enabling the'valve to operate with maximum` eiiiciency without restricting or impeding iiow therethrough.

Another object of the invention is to provide a control unit for use with a pressure fluid operated valve for positively controlling the opening and closing time of the valve.

A still further object of the invention is to provide an automatic control means for fluid pressure operated devices which is comparatively simple inconstruction, relatively inexpensive to manufacture, and which requires no substantial servicing.

Other and further objects of the invention will be apparent from the following description, taken in conjunction with the accompanying drawings, in which: I

Figure l is a View partly in cross section of a valve including my novel control means for regulating the rate of opening and closing of the valve;

Figure 2 is a partial plan view of the valve shown in Figure 1; and

Figure' is an enlarged sectional view taken on the line 3-3 of Figure 2 through the valve control means.

Referring now to Figure 1 of the drawings, the letter B' indicates the valve body and the numerals I and 2", respectively, indicate the inlet and outlet chambers or openings of the valve. The letter C' indicates the cap of the valve and the letter D' indicates a circular diaphragm whose marginal portion is clamped between the body B' and cap C by any suitable number of cap screws 3l The body B is provided at its inlet side l" with a substantially vertical partition wall 4' forming the inlet chamber l" and an angular wall portion 5' cooperating with the wall 4' to form the outlet chamber 2". Thev wall portions 4' and 5'are merged to provide a circular opening 6 which is threaded and adapted to receive an annular valve seat 'l'. The valve seat 'l' is provided with a circular opening 8f which ares outwardly toward the bottom of the valve body as indicated at 9'. The upper surface of the valve seat 'I' adjacent the opening 8 is provided with a declining beveled portion l0' adapted to cooperate with a valve disc Il' to form a leakproof seal, as will be explained more fully hereinafter. I

The valve body B has a threaded opening I2 axially aligned with the opening 8 in the valve seatf'll An elongatedplug I 3' is threadedl into the opening. l2' and comprises a tubular guide portion 14": for thel lower end I5' of avvalve sten?.

S. The cap member C also has a recess I6' counterbored at l1 to receive a guide bushing I8 for the upper end I9' of the valve stem S". The recess I6 is located in the cap member C' so that it is axially aligned with the tubular guide portion I4 and the opening 8 of the valve seat. The valve stem S has a threaded portion 20' intermediate its lower end l5 and its upper end I9. The end I5' is of slightly less diameter than the tubular threaded portion 20' and has a snug sliding fit in the tubular guide portion I4 of the plug I3. The upper end I9 of the valve stem is enlarged to provide a shoulder at 2|' and, moreover, is snugly guided inA the bushing I8'. Thus, the plug i3 and bushing I8 are arranged to guide the stem S duringvertical movement.

An upper diaphragm supporting plate 22 is adapted to be received upon the stem S" and to abut the shoulder 2| with the upper side thereof. The upper side of the-diaphragm D' is engaged with the lower side of the plate 22 and is provided with an aperture through which the valve stem S" extends. The lower side of the diaphragm D is adapted to engage the upper side of a lower diaphragm supporting plate 24', and the valve stem S extends through a central boss 25 in said plate. The lower supporting plate 24 is also provided with a channel 26' formed in the lower side thereof to receive the disc Il previously referred to. A combined clamping member and choke-washer 28' is adapted to be mounted upon the stem S" and to engage the inner marginal portion of the valve disc I I. Clamping nuts 29' are threaded upon the portion 20 of the valve stem S and serve to retain the valve stem, the diaphragm supporting plate plates 22' and 24', the valve disc I l' and the choke-washer 28 in assembled relation with the diaphragm D. The outer diameter of the clamping member or chokewasher 28 is preferably only slightly less than that of the opening 8' of the valve seat l'. In a 6 inch valve, for example, the maximum radial clearance may be only three or four thousandthsof an inch. The peripheral edge of the chokewasher 28 is preferably rounded, as indicated at 3D', and is tapered outwardly and upwardly from said rounded portion to substantially its upper outer'edge, as indicated at 3| (and shown to an enlarged scale in Figure 2 of my parent application). The rounded and tapered peripheral portions of the choke-washer 28' serve to gradually cut oi the flow through the opening 8' and the beveled portion I of the valve seat I cooperates with the valve disc Il' to reduce eddying and to form a theoretical line contact sealV whereby tight, smooth and chatterless operation of the valve is obtained. v

The tubular guide I4 `with the lower end of the valve stem S is pierced by one or more transverse openings 32 arranged to establish communication between the outlet chamber l2" of the valve and the interior of the guide. These openings obviously provide for free and unrestricted movement of the lower portion I' of the valve stem in the guide I4'. n

The valve body B', on the outlet side thereof, is provided with a passageway 34 adapted to receive one end of a short section of tubing'35'. The tubing 35' extends through an opening in the diaphragm D and projects into a passageway 31 formed in the cap member C'. A control unit 60 is mounted on the cap member C' for controlling the opening and closing actions of the valve, respectively, as will be set forth more fully hereinafter. YA passageway 43 in the cover C es- 4 tablishes communication between the control unit 60 and a diaphragm pressure chamber 45 formed in said cover. A groove 46 communicates with the passageway 43' and will provide for admission of fluidinto the pressure chamber 45 even though the diaphragm D may be engaged with the inner face of the cover C. A spring 6l is interposed between the upper end of the valve stem S and a plug 62 threaded into a boss 63 formed upon the'cap member C. The spring 6I may be desirable in some instances to provide an auxiliary differential pressure eiective upon the upper end of the stem S" to assist in closing the valve, although it will also be effective to oppose the opening of the valve to some extent. However, more important than these is the function of the spring 6I to oiset any possible upward force resulting from the buckling eiect of the diaphragm' which might require a substantial excess of pressure in the diaphragm pressure chamber 45 above that in the inlet chamber I to initiate the downward movement of the diaphragm. Anl other important function of the spring 6| is to supplement the closing pressure in the diaphragm chamber 45 by providing an ever-present potential pressure sufficient to overcome the slightly increased resistance to closing as the choke member 20 and the valve disc Il are urged against the fluid flowing through the valve seat opening I8 to elect the final closing of the of the valve is so slight that, if the valve were to remain open, a back flow would occur. In such case, the spring will provide the pressure differential necessary to initiate the closing movement of the valve in order that no substantial back flow can occur.

The pressure fluid from the outlet chamber 2 may be transmitted to the diaphragm chamber 45 through passageways 34', 31', a passageway 43 and a groove 46 in the cover C'. before the fluid can enter the diaphragm chamber 45 it must pass through the control unit 6D.

The control unit comprises a body portion 65 and a base portion 66 which is mounted upon the cap C' by cap screws 61. A gasket 68 having openingsv aligned with the passageways 37 and 43 is clamped between the cap C and the base 66 in leakproof relation.

The structural details of the control unit are'l best illustrated in Figure 3. Here the body 65v has a base surface engaging the gasket 68 and is shown provided with passageways 69 and terl minating at their outer ends in said baser surface' andY adapted to be placed in aligned relation'with" the openings in the gasket 68 and the passage-1" ways 3,1 and 43' in the cap C. The passageway 69 communicates with a chamber ll inthe body relatively to the port 'l2 to regulate theV flow of fluid through said port.` A hollow nut v'I'l threadedly mounted on the boss l5 and one end of the needle valve 13 projects through an opening in said nut. The end of the needle valve-'I3 maybe provided with a slot 86 tofacilitate adjustment thereof.

A bushing 8l is mounted in the housing "65at the upperend 'of the chamber'iliandits vupper I edge 82 adapted to forma seat for a checlf However.

wam

valve disc 83. A stem 84 extends upwardlyfrom the'disc 83 and one end of aspring 85 is connected thereto. The opposite end of said spring is received in a recess 86 formed in the base of a plug 81 threadedly mounted in a boss 88 projecting upwardly from the body E5. The construction of the check valve disc 83 and spring 85 is such that said disc is permitted to leave its seat 82 when occasion requires, but is constrained from becoming misaligned with said seat by said spring.

The passageway 'l0 communicates with a chamber 9| through a port 92. A needle valve 93, Similar to the needle valve '13, is adjustably mounted in a boss 95 to control the flow of iluid through the port 92.

A bushing is mounted in the housing 95 at the top of the chamber 9| and its Uupper edge forms a seat |02 for a disc type check valve |03 similar to the check valve 83. A spring |05 is connected to the disc check valve |03 and is associated with the plug |91 in a manner similar to the spring 85.

It will be observed from Figure 3 that theA passageways 69 and 10 overlap or cross each other in non-communicating relation, as indicated at |08, the passageway l0 communicating with a chamber |09 in which the check valve 83 is mounted. The passageway 69 communicates with a chamber |0 in which the check valve |03 is mounted.

The arrows in the various passageways of the control unit shown in Figure 3 indicate the direction of flow of the fluid when the main valve is opening. Thus, it will be apparent that, when the valve stem S is rising, fluid will be expelled from' the diaphragm chamber 45 and will ilow through passageway 43 into the passageway 10 ofthe controlunit. From here, the fluid will pass through the port 92 at a rate permitted by the needle valve 93. The pressure of this uid will lift the check valve |03 from its seat and permit the iluid to flow into the chamber ||0, from whence it will flow into the passageway 59 and then drain back into the outlet chamber 2" through the passageways 31 and 34. It will be observed that, while the fluid from the passageway 10 raises the check valve |03 from its seat against the pressure of spring |05, the pressure of this fluid transmitted to the chamber |09 acts upon the check valve 83 to maintain it tightlyiagainst its seat. Y

During the closing of the valve, the operation would be the reverse. That is to say, iiuid will flow from the outlet chamber 2" through the passageways 34 and 31' into the passageway 69 of the control unit. The fluid will then flow through the ports 'l2 at the rate permitted by the needle valve 13 and will raise the check valve 83 from its seat against the pressure of the spring 85. Simultaneously, fluid from the passageway 69 will act downwardly upon the check Valve |03 and maintain it upon its seat.

It will be apparent from the foregoing that adjustment of the needle valve 93 will control the rate of opening of the main check valve and that the adjustment of the needle valve 13 will control the rate of closing of the main check valve. The rate of closing and the rate of opening may thus be independently adjusted to provide, for example, a valve operation in which the main valve will close gradually and at a very slow rate to slowly cut 01T the flow of fluid through-the valve, and the opening of the valve may be controlled so that it will occur at a relatively faster rate.

13 and 93 have been set. When the needle valveVV 13 is adjusted to provide for slow closing of the valve, the valve will close gradually against attempted back flow through the main valve and thus eliminate noisy operation and any possibility of-the valve slamming shut.

well as a uniform rate of opening of the main valve.

It will be understood that the principles of the invention may be embodied in control meansv different from that illustrated herein without departing from the spirit of the invention an the scope of the appended claims.

What I claim is: 1. A unit for yuse in controlling'the flow of operating fluid to and from a pressure responsive device, comprising: a body having a base surface,

said body having a pair of generally upright passageways and a pair of check valve chambers formed therein, each of said check valve chambers having an inlet side and an outlet side, said passageways terminating at their lower ends in said base surface and at their upper ends in one of the outlet sides of said check valve chambers, said body having a port communicating with each of said passageways at a point between said base surface and said check valve chambers; separate needle valves controlling the rate of flow of fluid from each of said passageways into its associated port; a pair of check valves, one in each of said check valve chambers arranged to seat in the same direction, said ports respectively establishing communication between the passageway associated therewith and the inlet side of the check valve chamber at the upper end of the other passageway, said needle valves being independently adjustable to control the flow of fluid in one direction from one of said passageways-into the other at a given rate and to control the ilow of fluid in the opposite direction from said other passageway into said first-mentioned passageway at a relatively greater rate.

2. A unit for use in controlling the flow of operating fluid to'and from a pressure responsive device, comprising: a body having a pair of passageways and a pair of check valve chambers formed therein, each of said check valve chambers having an inlet side and-an outlet side, saidA passageways crossing each other in non-communicating relation and respectively terminating in one of the outlet sides of said valve chambers, said body having a port communicating with each of said passageways and extending laterally therefrom and communicating with the inlet side of the valve chamber associated with the other passageway; a needle valve mounted in said body in alignment with each of said ports and respectively controlling the rate of uid flow from each of said passageways into its associated port; Valve means in one of said valve chambers for establishing communication between one of said passageways and the port of the other of said passageways for flow in only one direction therethrough; and other-valve means in the other of said valve chambers for establishing communication between the other of said passageways and the port of said one passageway for ow only in the opposite direction therethrough,

The control vunit i 60 thus provides for a uniform rate of closingas man insfaidjdirections at different rates. Y

3. A 'unitfor umformiy controuingthesu'ppiy saia-ae'edlmvesbeingadjusamteeoafornat# of operating fluid to and the exhaust of spent operating fluid from a pressure responsive device, comprising: a body yhaving a base surface, said body having a pair of passageways formed therein to' admit uid into and to discharge iiuid frorn said Lbod'y and avpair of check valve chambers each l,having an inlet side and an outlet side,

each of; said passageways terminating in said passageways being in communication with the inlet side of the check valve chamber at the'inner endA of the Vother passageway; separater4 needle valves for controlling the rate ofl iiow `from said Y Y 8 disposed in substantially the saine hdrzn'tal' plane; a seat fora check valve in each of"sailu check valve chambers; a separate port communi? eating with each of said passageways, the port'of'v the respective passageways being in communica;- tion with Vthe inlet side of the check valve cham ber at the end of the other passageway; separateV needle valves for controlling the rate of ow from said passageways into their respective ports; a check valve including a disc in each ofY said checkvalve chambers engageable with the seat therein. said check valves seating in the same direction;- and spring means maintaining each check valve 1 disc in substantial alignment with its associated seat and yieldably urging the same'into engagement therewith.

6. A unit for usev in controlling the flow of operating fluid to and from a pressure responsive 'f device, comprising: a body having a pair of pas-l passageways into their respective ports;` and a check valve in'each of saidcheck valve cham# bers, said check valves seating in the same direction.

4. A unit for uniformly controlling the supply of operating' iiuid: to and the exhaust of spent operating fluidA from a pressure responsive device, comprising: a bodyhaving a pair of passageways formed therein tol admit fluid intov and to discharge fluidfrom said body, said passageways crossing each other adjacent their inner ends in non-communicating relation and extending'in opposite directions at saidinneriends; a separate port opening into each of said passageways at a point spaced from said inner ends; separate needle valves'for controlling the rate' of flow from said passageways into their respective ports; and

a pair of check valves, the check valves respectively being disposed between the inner end of one passageway and the port of the otherv pas# y sageways formed therein to admit iiuid into and' to discharge fluid from said bodyV and a pair of upright check valve chambers each having an inlet side and an outlet side, Aeach of said passageways having an end terminating at the outlet side of a diierent one of said check valve cham? bers; a removable plug in said 'body providig'a Y closure for the upper end of each of said check`E4 valve chambers; a check valve in each of said"- .check valve chambers, said check valves seating' REFERENCES CITED i The following references are of record in th le of this patent:

UNITED STATES PATENTS Number Name Date 840,876 Steedman Jan.8, 1907 840,877 Steedman Jan. 8,1907

1,923,127 Veenschoten Aprl 22;' 1933 2,167,623 Britter Aug. 1,y 1939 valve chambers, said check valve chambers being 

